Description: The overall objective of the Histology Core is to provide histopathology services, so that pathophysiological invesfigafions will be backed by quantitative morphological data The Core provides expertise and state-of-the-art technical services for histologic and cytologic analyses, and the data obtained are presented in a visual and/or quantitative format. The Histology Core is a continuation ofthe Celt,Tissue, and Imaging Core in the previous cycle. The Core has provided reliable imaging of lung cells and tissues, and will continue to provide this essential service in the revised application. Cells and cell components can be easily visualized [e.g.,neutrophils, T cells, and macrophages (and their granules), collagen, elastin, capillary endothelial cells and pericytes, and basement membranes]. The Core also keeps abreast of new developments in histopathology and helps participating faculty apply the appropriate techniques to their research projects. Finally, the Core helps the project leaders prepare images for publication and presentation. It is important to emphasize that this Core's services extend far beyond those of just producing tissue sections. The Core provides knowledge, expertise and interpretation ofthe histological and cytological preparations produced. It helps the investigators evaluate and design experiments that use these techniques. It also trains investigators, postdoctoral fellows, graduate students and technicians in animal necropsy, Tissue fixafion, histopathology, immunohistochemistry, in situ hybridizafion, and image analysis. The Core staff can also provide assistance in the development of histopathologic and morphometric techniques as new findings make them necessary.